Putting a torch to untreatable wastes

Toxfree’s Narangba site is home to exclusive destruction technologies – the Plascon and indirect thermal desorption (ITD) – that are specifically designed to treat intractable, or hard to deal with, waste.

Toxfree Narangba was approached by a customer to destroy 11 tonnes of Arsenic Trioxide and Organochlorine Pesticides (OCP’s). This waste had been left untreated for 20 years because it was believed that no safe or compliant treatment option was available, and it was too expensive to dispose of. Arsenic Trioxide and OCP’s are lethal products by themselves, and combined they are considered by many to be untreatable.

OCPs are pesticides used mostly between 1940 and 1960 in agriculture and mosquito control. PCBs were previously used as dielectric and coolant fluids in heat transfer fluids, electrical apparatus and carbonless copy paper. OCP’s and PCB’s are no longer produced and their use is banned, as we now know they are harmful to humans and animals, however stocks of these products still exist. The Narangba site is the only location in Australia licenced to destroy OCP’s and pure Polychlorinated biphenyl (PCB).

The process for stabilising and treating the 20-year-old Arsenic Trioxide and OCP involves decanting the waste into ITD trays and then cooking it at 350 degrees Celsius. This process liberates the OCP but leaves the Arsenic intact, it is then desorbed into a collection liquid that is treated through the Plascon. The Plasma arc torch, inside the Plascon machine, achieves high enough temperatures to completely destroy hazardous substances, the only by-product is salty water.

The remaining solid, containing arsenic, is then chemically immobilized. The immobilization mixture is set aside to cure, regular testing occurs and once all outcomes are achieved the mixture is sent for final disposal. The customer was relieved to finally have this particular waste disposed of in a safe manner, without causing harm to the environment.

The ITD processes between 100 and 130 tonnes a year and the Plascon can process 25 kilos per hour, 24 hours a day. The Narangba site services the whole of Australia and some international clientele, as it is the only site licenced to destroy OCP’s and pure PCB’s. Specialised waste management is key to stopping pollution to the Earth, if you have a difficult waste stream contact Toxfree today.